MARINE FOOD FISHES. 31 



destroyed, aud if this rule be applied to the 220,000 cases which constituted the product 

 of the fishery for the year 1889, we have a number of 110,000,000,000 as the wanton 

 destruction of ova which it is possible, by the use of this simple means (Mr. Nielsen's 

 incubators) to save, or at any rate, in some small measure ; for even a saving- of one per 

 cent of such a total, represents a number the magnitude of which figures fail to bring- 

 home to the mind." 



The propagation of codfish aud lobsters is but a part of the work of the Fisheries 

 Commission in Newfoundland. They diffuse information regarding the cure of codfish, 

 the cure and packing of herrings ; aud construct and enforce rules and regulations for all 

 the fisheries designed to protect and improve them, while they aim at maintaining a 

 careful guardianship over the salmon rivers. In the herring fishery they have already 

 accomplished an improvement which will be of immense value to the colony. 



The remainder of this paper may be usefully occupied with some remarks on the 

 development of the ova of the codfish and lobster, derived from observations at the Dildo 

 hatchery. 



The great majority of our marine food fishes deposit their eggs near the surface of the 

 sea. These eggs are extremely buoyant, transparent as crystal, and, while in a living aud 

 healthy condition, will not sink. On the loss of their vitality, however, they .sink to the 

 bottom. The specific gravity of the cod ova is delicately adjusted to the salinity of the 

 water. If the sea water on the surface becomes mixed with fresh water, as will occur 

 after continuous heavy rains, the ova sink down uutil they meet water of a suitable 

 salinity and density. When the fresh water has evaporated they will rise and lloat on 

 the surface, their constant tendency being upwards, so as to come under the genial 

 influence of the solar light and heat. These delicate little eggs have first to mature in the 

 ovary of the mother-lish, aud when ripened in this receptacle, the capsules which encom- 

 pass them burst, aud the ova are discharged into the water, looking like small transparent 

 bubbles to the naked eye, aud behaving iu the sea just as soap-bubbles do in the air, 

 dancing freely about when the water is agitated. The ripened milt of the male fish, 

 containing the spermatozoa which are necessary to the impregnation of the egg, is 

 discharged into the same waters and must come into contact with the ova before they 

 can develop into fishes. It is marvellous to look upon one of these little transparent 

 embryos of the cod as it bursts from the egg, barely A'isible to the naked eye, and weighing 

 only the fraction of a grain, and to think that from it Mall be developed the lordly codfish, 

 weighing forty, fifty or even sixty pounds. This growth takes place in three or four 

 years, in which time it becomes perhaps half a million times weightier than at birth. It 

 surpasses even the marvellous growth of the salmon which Frank Buckland considered 

 to be the most rapidly increasing of all animals. He tells us that a salmon three days old 

 is two grains in weight, and when it comes to maturity it may weigh thirty pounds and 

 will then have increased 115,200 times the weight it had at first. But the cod sitrpas.ses 

 this, starting from an embryo which is a mere fraction of the young salmon's weight. 



The ovaries of the codfish are very largely developed, filling nearly the whole oft he 

 abdominal cavity. A very large cod has been known to contain nine millions of eggs. 

 But it must be taken into account that these eggs are small, exceedingly delicate, and 

 exposed to greater dangers during the course of development than the ova offish which 

 carry a smaller number. The latter are larger — as in the salmon — hardier and better 



